1. Field of the Invention
The present invention relates to motor vehicles and in particular to a motor vehicle with an automatic transmission.
2. Description of Related Art
Methods for controlling a transmission have been proposed. Leising (U.S. Pat. No. 4,938,102) is directed to a method of adaptively scheduling a shift or inhibiting a shift until the engine speed is at least equal to or greater than the output speed of the target gear. Leising teaches this method to prevent any negative torque, which further eliminates any “clunk” in the drivetrain in an automatic transmission system.
According to Leising, a power-plant (engine) reversal situation or condition exists when the wheels of the vehicle drive the engine through the transmission. The methodology taught by Leising includes steps of determining if the engine speed is at least equal to or greater than the output speed of the target gear to determine if power-plant reversal may occur. If a power-plant reversal situation exists, the methodology of Leising prevents the shift from occurring.
Leising lacks a method for preventing shock that may occur when a one-way clutch is in an overrun condition. There is a need in the art for a system and method that addresses the shortcomings of the prior art discussed above.